Frame corner rounding apparatus



Aug. 1, 1967 A. FURTADO ETAL FRAME CORNER ROUNDING APPARATUS 3 Sheets-Sheet 1 Filed Jan. 18, 1965 INVENTOR. ARTHUR FURTADO ISAAC RIOS JR. WARREN R. WISE-CARVER WW ATTORNEYS Aug. 1, 1967 A. FURTADO ETAL FRAME CORNER ROUNDING APPARATUS 5 sheets sheet 2 Filed Jan. 18, 1965 INVENTOR. ARTHUR FURTADO lsAAc RIOS JR. WARREN R. WISECARVER mam ATTORNEYS Aug. 1, 1967 A. FURTADO ETAL 3,333,614

FRAME CORNER ROUNDING APPARATUS Filed Jan. 18, 1965 5 Sheets-Sheet 74 INVENTOR.

ARTHUR FURTADO ISAAC RIOS JR. 1.31 2 WARREN R. WISECARVER ATTORNEYS United States Patent 3,333,614 FRAME CORNER ROUNDING APPARATUS Arthur Furtado, 1125 Macaulay, and Isaac Rios, IL, 45

W. 17th, both of Antioch, Calif. 94509, and Warren R. Wisecarver, Walnut Creek, Calif.; said Wisecarver assignor to said Furtado and said Rios, doing business as ABC Frame & Pallet Co.

Filed Jan. 18, 1965, Ser. N0. 426,121 8 Claims. (Cl. 144-141) This invention relates to apparatus for cutting arcuate corners on a wooden frame of the type used in constructing bedding structures such as box springs and innerspring matresses.

Most innerspring mattresses and box spring assemblies include a rectangular wooden frame to which the internal parts and the exterior fabric covering are secured. Substantial commerce in such frames exists. Such frames are preferably of uniform size, both to expedite construction of the mattress or box spring and to insure uniformity in the finished product. Moreover, the frame must be substantially free from sharp corners or edges to avoid tearing the covering fabric and to avoid danger to the user of the finished product.

Therefore, it is an object of this invention to provide a semi-automatic apparatus that is useful in the construction of such frames and which apparatus promotes attainment of the above enumerated desiderata. A satisfactory embodiment of the apparatus is described in detail hereinbelow and includes a pair of confronting channel members for defining a path along which the assembled frame is moved and a stop member in the path for establishing the frame in a fixed working position. At the working position are provided two pivotally moving arm assemblies, each having associated therewith a rotatively driven cutter. Semi-automatic control devices are provided for clamping the frame upon its arrival at the working position and for actuating the cutter arm assemblies to move the cutters in an arcuate path with respect to the frame corner.

A further object is to provide a more eflficient and more rapidly operating apparatus which does not sacrifice accuracy. Such object is achieved in the present invention by providing a pneumatic control system which clamps the frame in a fixed working position, moves the cutters in a circular path about the corners of the frame, and then automatically restores the cutters to the starting position and releases the clamping apparatus to permit withdrawal of the frame. As a result of such automatic operation, the time necessary for forming rounded corners is materially reduced.

In one apparatus designed according to the present invention, installation of the apparatus effected a saving of 6 /2 man hours per day and permitted frames to be finished at the rate of approximately 100 per hour, a rate almost twice that possible with prior art techniques. Obviously, such man-power savings permit a material cost reduction in providing the frames.

These and other objects will be more apparent after referring to the following specification and accompanying drawing in which:

FIG. 1 is a plan view of one satisfactory embodiment of our invention;

FIG. 2 is a front elevation view of the apparatus of FIG. 1;

FIG. 3 is an enlarged cross-sectional view taken substantially along line 3-3 of FIG. 1 and showing in enlarged detail some of the operative parts of the present apparatus;

FIG. 4 is a view in enlarged scale taken along line 44 of FIG. 1;

FIG. 5 is a perspective view of one corner of a typical frame that is adapted to be finished by the apparatus of the present invention.

FIG. 6 is a schematic diagram of one satisfactory control system for the apparatus; and

FIG. 7 is a view taken substantially along line 77 of FIG. 2 showing details of the structure.

Referring more particularly to the drawings, reference numeral 12 indicates generally a base frame for supporting the apparatus. Secured to base frame 12 is an angle member 14 having a horizontal leg 16 and a vertical inwardly facing leg 18. A second angle member 20 is secured to the base and has a horizontal leg 22 disposed in co-planar relationship with horizontal leg 16 and a vertical leg 24 in confronting relation to vertical leg 18. Angle members 14 and 20 constrain a bed frame ,assembly F therebetween and define a path for slidably supporting the frame. Transversely of the path and secured to base 12 is one or more stop members 26. The stop members establish a working position for frame F when the frame abuts the stop members. Associated with the working position is a limit switch 28 for sensing the arrival of the frame in the working position. Angle members 18 and 20 terminate, as at 30, rearwardly of stop member 26 so as to support frame F with forward corners thereof in an unobstructed condition.

Secured to frame 12 and extending thereabove is a bracket 32 for supporting a clamping dog 34 that is pivotally mounted on the bracket by a shaft 36. Dog 34 has a rounded nose 38 so that when it bears on the top surface of frame F the frame surface will not be defaced. Pivotally secured to dog 34 at the end remote from nose 38 is a rod 40 of a pneumatic piston 42. The body of piston 42 is secured to the frame by a conventional clevis joint 44. As can be seen most clearly in FIG. 4, when rod 40 is extended from cylinder 42, dog 34 moves into engagement with frame F. Such action is initiated when the frame contacts limit switch 23; one satisfactory control system for securing the desired mode of operation will be described in detail hereinafter.

Affixed to frame 12 and extending below each side of the path defined by angle members 18 and 20 is a vertical pivot shaft 46 which is secured at its upper and lower end to frame 12. It will be noted that each shaft 46 is disposed on a line that bisects the corner angle of frame assembly F when it is in the working position (see FIG. 1). Supported for pivotal movement on each shaft 46 is a-carriage frame 48, bearing blocks 50 being secured to the carriage for affording pivotal movement of the carriage with respect to shaft 46. As more clearly seen in FIG. 7, carriage 48 includes an upper horizontal structural member 52 and a lower horizontal structural member 54 spanned by vertical members 56, 58 and 60. Extending between frame members 56 and 58 are motor support channels 62 on which is mounted an electric motor 64. Motor 64 is so mounted that its shaft 66 extends vertically downwardly and has mounted at the lower extremity thereof a pulley 68, or the like. On the opposite end of carriage frame 48 a saw shaft 70 is suitably journaled, and has at the lower end thereof a pulley 72 in alignment with pulley 68. Belts 74 span the pulleys to transmit power therebetween. On the upper end of shaft 70 and secured thereto for rotation therewith is blade stack 76 composed of a plurality of identical saw blades. As can be seen more clearly in FIG. 3, the saw blade stack includes individual circular saw blades 78 between which are provided spacing washers 80. The thickness of washers 80 is chosen in accordance with the set of the teeth of blades 78. It will also be noted from FIG. 3 that the lower blade 78 has a concave cutting edge of slightly greater diameter than the remaining blades so as to form a convex corner at the lower edge of the bed frame assembly F. It will accordingly be undera rod 86 secured to carriage frame 48 by a clevis joint 88. Movement of rod 86 effects pivotal movement of carriage 48 through a 90 arc to form a radius cut on the bed frame assembly corner.

Carriage frame 48 is normally, i.e. when not cutting, disposed in the position shown diagrammatically in FIG. 1. That is, the carriage is pivotally positioned so that the peripheries of the blades 78 are tangent to the leading or end edge of bed frame assembly F. As will be explained in detail hereinbelow, each carriage is pivoted 90 after arrival of bed frame assembly F at the working position, i.e. against stops 26. Such arrival is sensed by limit switch 28, the normally open contacts of which are closed upon arrival of the bed frame in the working position. Power is supplied through such contacts to a solenoid coil 90. which operates ganged air valves 92 and 94. The air valves control air supplied through a line 96 from a compressed air source, not shown, and exhausted through an exhaust line 99. The valves 92 and 94 are positioned as shown in FIG. 6 when solenoid coil 90 is de-energized and are moved clockwise upon energization of the coil. In the position shown in the figure, all cylinders, that is cylinders 42 and 82, are retracted so that frame clamping dog 34 is released and carriage frames 48 position saw blades 78 tangent to the end member of the frame assembly F. In such position compressed air is supplied through valve 94 to an air line 98. At this position air is exhausted through valve 92 through an air line 100.

Electric power is supplied to the contacts of limit switch 28 from a power source 102 through parallel normally closed contacts 104 and 106. Contacts 104 and 106 indicate limit switches that are operated after pivotal movement of carriages 48 through a 90 arc. Accordingly, when both the carriages 48 have traversed a 90 arc, the power to solenoid coil 90 will be interrupted by the opening of both limit switches 104 and 106, as a consequence of which valves 92 and 94 will be returned to the normal position, i.e. the position shown in FIG. 6.

The operation of our control system is as follows. With the elements of the apparatus positioned as shown in FIG. 6 and with both motors 64 running to drive blades 78 in rotation, an operator manually moves a bed frame assembly F along the path delineated by members 14 and 20. When the frame arrives at the working position against stop member 26, limit switch 28 is operated and completes the circuit from battery 102 to solenoid coil 90. Valves 92 and 94 are thereby rotated to supply compressed air to line 100 and to exhaust air from line 98. Application of air to line 100 causes cylinders 42 to drive dog 34 into the clamping position. Such clamping action occurs almost instantaneously due to the insignificant intertia possessed by the dogs 34 and the relatively short length of the air lines from valves 92 and 94 to the cylinders 42. Application of the compressed air to line 100 subsequently operates hydraulic cylinders 82 in a manner to drive rods 86 outwardly of the cylinder. Such action pivots carriages 48 and therefore moves saw blade stack 76 in an arcuate cutting path around the corner of the frame. When 90 of such pivotal movement has occurred, limit switches 104 and 106 are opened. Each carriage 48 has associated therewith an individual limit switch so that, should one of the saws encounter a knot or the like thereby delaying arcuate movement of the blade, clamping of the frame F in a Working position will not be terminated until both corners have been rounded. When both switches 104 and 106 are opened, power to solenoid coil 90 is released and valves 92 and 94 return to the normal position, thereby releasing stood that as carriage frame 48 is pivoted 90, the cutting W clamps 34 and permitting removal of the bed frame assembly and insertion of the other end of the bed frame assembly into the apparatus. It will be seen therefore, that arcuate cuts on two corners of frame F are effected in a single operation.

Our improved apparatus is adapted for ready adjustment to accommodate frame assemblies of different widths. For example, a normal single bed mattress frame is approximately 36" in width, whereas double beds and so-called queen size and king size beds require wider frames. To provide such adjustability we mount the left side 12 of frame 12 as viewed in FIG. 2 on a plurality of rollers 109.

The fixed or righthand side of frame 12 is provided with parallel transverse extensions 108 for slidably supporting rearwardly extending clamp members 110 and 112 that constitute a portion of frame assembly 12'. Rollers 113 are carried by members 110 and 112 to expedite such movement. Members 110 and 112 are provided with suitable clamping devices that are actuated by a hexagonal nut 114 or the like to afford sliding movement of left frame assembly 12 with respect to fixed frame assembly 12. Loosening hexagonal nut 114 permits frame subassembly 12 to be moved transversely thereby moving bed frame supporting member 14 and carriage 48 associated therewith on rollers 109 and 113. Accordingly, bed frames of different widths can be accommodated by the apparatus. Associated with bed frame supporting member 14 are threaded adjusting devices 116 that are adapted to provide a fine adjustment after frame subassembly 12' is positioned in approximate location by clamping structures 110 and 112.

To promote a more complete understanding of the operation of the present apparatus there is shown in FIG. 5 the corner of a typical frame assembly F. The frame is composed of a longitudinal member 120 which is typically made of l x 4 pine or fir. Intersecting the lastnamed member at 90 and secured thereto by a conventional lap joint is a transverse or end member 122 which is typically formed of the same type and size lumber. Filler members 124 and 126, typically formed of 1 x 2 lumber, are secured to the longitudinal and transverse frame members. Spanning the frame transversely thereof and secured opposite ends to longitudinal frame member 120 are a plurality of transverse support members, one such member being fragmentarily exemplified at 128. It will thus be seen that the corner of the frame is square and relatively sharp when the frame assembly F is first made up. The apparatus of the present invention, however, forms a radius or arcuate out along a path indicated by broken line of FIG. 5. By virtue of lowermost blade 78' of stack 76 a radius is formed at the lower edge 132 of the rounded corner. Accordingly, when fabric is stretched over the frame and secured to the lower surface thereof, such fabric is not torn because the edge 132 is rounded or relieved.

Thus it will be seen that we have provided an apparatus which is rapid, simple and uniform in operation and which is adjustable to accommodate frames of different sizes. Because of the semi-automatic control system in our apparatus, the time necessary for rounding the corners on a bed frame assembly is materially reduced. Accordingly, by the use of our apparatus bed frame assemblies of superior quality and lower cost are attainable.

Although one embodiment of our invention has been shown and described, it will be apparent that other adaptations and modifications can be made without departing from the true spirit and scope of the invention.

What is claimed is:

1. Apparatus for forming arcuate corners on a rectangular wood frame assembly comprising means for supporting said frame assembly for movement along a path parallel to two opposite sides of the frame, means for arresting said frame assembly in said path in a working position, means responsive to arrival of a frame assembly in said working position for clamping the frame assembly in the working position, said frame assembly supporting means being so formed that the forward corners of the frame assembly are substantially unobstructed when in the working position, a cutter assembly associated with each forward corner, each said cutter assembly including a carriage structure, means for mounting said carriage structure for pivotal movement about an axis normal to and beneath said path, a cutter rotatively mounted on said carriage structure, means on said carriage structure for rotatively driving said cutter, said cutter and said carriage structure mounting axis being disposed with respect to said corner so that on pivotal movement of said carriage structure said cutter defines an arcuate path generally tangent to the side of said frame assembly, and means responsive to the actuation of said clamping means to pivotally drive said carriage structure to move the cutter in an arcuate path through the corner of the frame assembly.

2. Apparatus for forming arcuate corners on a wooden frame of the type having a rectangular peripheral shape with four sides intersecting to form pairs of adjacent right angle corners, said apparatus comprising first and second mutually confronting guide members for defining a frame feed path, a stop member for arresting said frame in said path in a working position at which each corner of one said pair of frame corners is disposed in an unobstructed condition, first and second rotatable cutting blades, one blade being associated with each unobstructed corner, first and second carriages for carrying respective said blades, means for mounting said carriages for pivotal movement relative an axis so spaced from said blades that on pivotal movement of said carriages said blades describe an arcuate path tangent to the sides of said frame defining a corner, means carried by said carriages for driving said blades, and means responsive to arrival of said frame at the working position. to pivotally move said carriages in cutting movement around the frame corner.

3. Apparatus for simultaneously rounding two corners of a frame that has an end edge and two side edges extending normal to said end edge at the corners, said apparatus comprising means for constraining said frame for movement along a path parallel to said side edges, means disposed Within the path for arresting said frame in said path in a working position, a rotary cutter associated with each said frame corner, a car-riage structure for supporting each said cutter, means for mounting each said carriage structure for pivotal movement about an axis so spaced with respect to said corner when in the working position that said blade describes an arcuate path tangent to the end edge and side edge defining the corner, means normally maintaining said carriages in a position at which said cutters are tangent to the end edge of said frame, means responsive to arrival of said frame in the working position for clamping the frame in the working position, and means responsive to actuation of said clamping means for pivotally driving said cutter in an arcuate path so that each corner is rounded.

4. Apparatus in accordance with claim 3 in combination with means for adjusting said frame constraining means to adjust the width of said path, one said cutter supporting carriage structure being movable with said adjusting means to maintain said cutters fixed position with respect to the frame corners irrespective to the width of said path.

5. Apparatus according to claim 3 wherein said frame clamping means includes a limit switch operable by said frame on arrival in the working position, a clamping dog engageable with the end edge of the frame, and a pneumatic actuator responsive to actuation of said limit switch for moving said clamping dog into engagement with said end frame edge.

6. Apparatus according to claim 3 in combination with a limit switch associated with each said carriage structure for sensing completion of pivotal movement of said carriage structure, and means responsive to said limit switch for releasing said clamping means and returning said cutter to the starting position thereof.

7. Apparatus for forming arcuate corners on a wooden frame of the type having a rectangular peripheral shape with four sides intersecting to form pairs of adjacent right angle corners, said apparatus comprising means responsive to the arrival of said frame assembly at a working position for maintaining said frame in said working position, first and second rotatable cutting blades, one blade being associated with each right angle corner, first and second carriages for carrying respective said blades, means for mounting said carriages for pivotal movement relative to an axis spaced from said blades so that on pivotal movement of said carriages said blades describe an arcuate path tangent to the intersecting sides of said respective frame corner, means carried by each of said carriages for driving said blades, and means responsive to arrival of said fame at the working position to pivotally move said carriages in cutting movement around the frame corner from a first position tangent to one of said intersecting sides to a second position tangent to the other of said intersecting sides.

8. Apparatus for forming at least one arcuate corner on a rectangular wood frame assembly comprising: means for supporting said frame assembly in a working position, means responsive to the presence of a frame assembly in said Working position for clamping the frame assembly therein, a cutter assembly associated with at least one corner of said wood frame assembly, said cutter assembly including a carriage structure, means for mounting said carriage structure for pivotal movement about an axis normal to and displaced from said working position, a cutter rotatably mounted on said carriage structure juxtaposed said working position, means upon said carriage structure for rotatably driving said cutter, said cutter being disposed with respect to said corner so that on pivotal movement of said carriage structure said cutter de fines an arcuate path generally tangent to sides of said frame assembly which form said corner, and means responsive to the presence of a frame assembly in the working position to pivotally drive said cutter in an arcuate path through an angle of about 90 at said frame assembly corner.

References Cited UNITED STATES PATENTS 78,200 5/1868 Flory 144-141 2,594,548 4/1952 Flick 143-465 X 2,635,655 4/1953 Linstead 144134 DONALD R. SCHRAN, Primary Examiner. 

1. APPARATUS FOR FORMING ARCUATE CORNERS ON A RECTANGULAR WOOD FRAME ASSEMBLY COMPRISING MEANS FOR SUPPORTING SAID FRAME ASSEMBLY FOR MOVEMENT ALONG A PATH PARALLEL TO TWO OPPOSITE SIDES OF THE FRAME, MEANS FOR ARRESTING SAID FRAME ASSEMBLY IN SAID PATH IN A WORKING POSITION, MEANS RESPONSIVE TO ARRIVAL OF A FRAME ASSEMBLY IN SAID WORKING POSITION FOR CLAMPING THE FRAME ASSEMBLY IN THE WORKING POSITION, SAID FRAME ASSEMBLY SUPPORTING MEANS BEING SO FORMED THAT THE FORWARD CORNERS OF THE FRAME ASSEMBLY ARE SUBSTANTIALLY UNOBSTRUCTED WHEN IN THE WORKING POSITION, A CUTTER ASSEMBLY ASSOCIATED WITH EACH FORWARD CORNER, EACH SAID CUTTER ASSEMBLY INCLUDING A CARRIAGE STRUCTURE, MEANS FOR MOUNTING SAID CARRIAGE STRUCTURE FOR PIVOTAL MOVEMENT ABOUT AN AXIS NORMAL TO AND BENEATH SAID PATH, A CUTTER ROTATIVELY MOUNTED ON SAID CARRIAGE STRUCTURE, MEANS ON SAID CARRIAGE STRUCTURE FOR ROTATIVELY DRIVING SAID CUTTER, SAID CUTTER AND SAID CARRIAGE STRUCTURE MOUNTING AXIS BEING DISPOSED WITH RESPECT TO SAID CORNER SO THAT ON PIVOTAL MOVEMENT OF SAID CARRIAGE STRUCTURE SAID CUTTER DEFINES AN ARCUATE PATH GENERALLY TANGENT TO THE SIDE OF SAID FRAME ASSEMBLY, AND MEANS RESPONSIVE TO THE ACTUATION OF SAID CLAMPING MEANS TO PIVOTALLY DRIVE SAID CARRIAGE STRUCTURE TO MOVE THE CUTTER IN AN ARCUATE PATH THROUGH THE CORNER OF THE FRAME ASSEMBLY. 